Profiling a Cylindrical Roller Bearing Oil-Film Thickness Distribution With Ultrasound

2015 ◽  
Author(s):  
Meng Li ◽  
Li Chen ◽  
Minqing Jing ◽  
Heng Liu ◽  
Yi Liu ◽  
...  
Keyword(s):  
Film Thickness ◽  
Thickness Distribution ◽  
Roller Bearing ◽  
Thickness Measurement ◽  
Ultrasonic Pulse ◽  
Lubricant Film ◽  
Maximum Speed ◽  
Oil Film ◽  
Cylindrical Roller Bearing ◽  
Cylindrical Roller

The rollers and raceways in cylindrical roller bearings are separated by an extremely thin lubricant film over a narrow region, which is critical to performance. The ultrasound method has been applied successfully to a range of bearings including journal and ball bearings. But the actual maximum speed that can be measured is limited by the repetition frequency of the ultrasonic pulse. Otherwise, a single measurement point cannot image the thickness distribution of the cylindrical roller bearing. This paper describes the measurement of lubricant-film thickness distribution in a roller bearing by moving the ultrasound transducer. A new ultrasonic pulser-receiver is used to get enough effective measurement points. For a range of loads and speeds, the oil-film thicknesses of four positions along the roller are measured. The influences of the rotating speed and radial load on the film thickness measurement are consistent with the theoretical predictions. The limits of the PRR used in measurements are discussed and the averaging effect of the transducer focal zone size is observed.

Ultrasonic Measurement of Cylindrical Roller Bearing Lubrication Using High Pulse Repletion Rates

2015 ◽  
Vol 137 (4) ◽  
Author(s):  
Meng Li ◽  
Heng Liu ◽  
Cong Xu ◽  
Minqing Jing ◽  
Wenhui Xin
Keyword(s):  
Film Thickness ◽  
Thickness Distribution ◽  
Roller Bearing ◽  
Lubricant Film Thickness ◽  
Rotor Vibration ◽  
Oil Film ◽  
High Pulse ◽  
Cylindrical Roller Bearing ◽  
Cylindrical Roller ◽  
Focal Zone

This paper describes a measurement of lubricant-film thickness in a roller bearing using a new ultrasonic pulser-receiver, which has a maximum pulse repetition rate (PRR) of 100 kHz. The experimental results show that a higher PRR can help to get more measurement points and more details of the oil-film thickness distribution. Furthermore, the influence of rotor vibration response for the oil-film thickness is discussed, which is in keeping with the simulation result. Finally, the limits of the PRR are discussed in detail and the effect of the transducer focal zone size is also observed.

Measurement of Oil Film Thickness in Cylindrical Roller Bearing by Ultrasound

2014 ◽  
Author(s):  
Kai Zhang ◽  
Qingfeng Meng ◽  
Wei Zhao
Keyword(s):  
Reflection Coefficient ◽  
Film Thickness ◽  
Roller Bearing ◽  
Piezoelectric Element ◽  
Elastohydrodynamic Lubrication ◽  
Spring Model ◽  
Oil Film ◽  
Rolling Element ◽  
Cylindrical Roller Bearing ◽  
Cylindrical Roller

This paper describes the measurement of oil film thickness between rolling element and inner raceway in cylindrical roller bearing. A fine piezoelectric element is bonded on the inner surface of the inner ring to measure the reflection coefficient of oil between rolling element and inner raceway. The quasi-static spring model is used to calculate oil film thickness from the corrected reflection coefficient data. Experiments are described on a simplified cylindrical roller bearing configured by one cylindrical roller, 11ø, and an inner ring from a NU209EM bearing. Reasonable agreement is shown over several loads and speeds with predictions from elastohydrodynamic lubrication (EHL) theory.

Analysis on Dynamic Characteristics of High Speed Cylindrical Roller Bearing

2011 ◽  
Vol 480-481 ◽  
pp. 980-985
Author(s):  
Yan Shuang Wang ◽  
Ning Ning Jin ◽  
Hai Feng Zhu
Keyword(s):  
Film Thickness ◽  
Dynamic Characteristics ◽  
High Speed ◽  
Rotational Velocity ◽  
Dynamic Performance ◽  
Roller Bearing ◽  
Engineering Application ◽  
Oil Film ◽  
Cylindrical Roller Bearing ◽  
Cylindrical Roller

A nonlinear dynamics analysis mathematical model for the high-speed cylindrical roller bearing was built up. Dynamic performance parameters were got by Newton - Raphson method . The rotational velocity regularities of rollers were analyzed at different radial loads. The distribution of minimum oil-film thickness and contact load between rollers and bearing ring raceway were obtained. The results showed that number of loaded rollers increased with the increase of radial loads at a certain speed. Rollers slip seriously at lower radial loads. The rotation speed was low. The minimum oil-film thickness between loaded rollers and inner raceways was less than that of outer raceways. The results were compared with the results of SHARBERTH and comparison was made with testing results. It showed that the dynamic characteristics analysis method of high speed cylindrical roller bearing was accurate, reliable,simple and convenient for practical engineering application.

scholarly journals Direct load monitoring of rolling bearing contacts using ultrasonic time of flight

2015 ◽  
Vol 471 (2180) ◽  
pp. 20150103 ◽  
Author(s):  
W. Chen ◽  
R. Mills ◽  
R. S. Dwyer-Joyce
Keyword(s):  
Roller Bearing ◽  
Time Of Flight ◽  
Ultrasonic Pulse ◽  
Ultrasonic Time ◽  
Rolling Element ◽  
Bearing Load ◽  
Load Monitoring ◽  
Rolling Elements ◽  
Cylindrical Roller Bearing ◽  
Cylindrical Roller

The load applied by each rolling element on a bearing raceway controls friction, wear and service life. It is possible to infer bearing load from load cells or strain gauges on the shaft or bearing housing. However, this is not always simply and uniquely related to the real load transmitted by rolling elements directly to the raceway. Firstly, the load sharing between rolling elements in the raceway is statically indeterminate, and secondly, in a machine with non-steady loading, the load path is complex and highly transient being subject to the dynamic behaviour of the transmission system. This study describes a method to measure the load transmitted directly by a rolling element to the raceway by using the time of flight (ToF) of a reflected ultrasonic pulse. A piezoelectric sensor was permanently bonded onto the bore surface of the inner raceway of a cylindrical roller bearing. The ToF of an ultrasonic pulse from the sensor to the roller–raceway contact was measured. This ToF depends on the speed of the wave and the thickness of the raceway. The speed of an ultrasonic wave changes with the state of the stress, known as the acoustoelastic effect. The thickness of the material varies when deflection occurs as the contacting surfaces are subjected to load. In addition, the contact stiffness changes the phase of the reflected signal and in simple peak-to-peak measurement, this appears as a change in the ToF. In this work, the Hilbert transform was used to remove this contact dependent phase shift. Experiments have been performed on both a model line contact and a single row cylindrical roller bearing from the planet gear of a wind turbine epicyclic gearbox. The change in ToF under different bearing loads was recorded and used to determine the deflection of the raceway. This was then related to the bearing load using a simple elastic contact model. Measured load from the ultrasonic reflection was compared with the applied bearing load with good agreement. The technique shows promise as an effective method for load monitoring in real-world bearing applications.

Simulation of hydrodynamic lubrication between cage pockets and rollers in cylindrical roller bearings

2014 ◽  
Vol 229 (14) ◽  
pp. 2551-2560 ◽  
Author(s):  
Fangbo Ma ◽  
Fengyuan Jiang ◽  
Qi An
Keyword(s):  
Rotation Speed ◽  
Hydrodynamic Lubrication ◽  
Roller Bearing ◽  
Angular Acceleration ◽  
Oil Film ◽  
Ring Rotation ◽  
Roller Profile ◽  
Cylindrical Roller Bearing ◽  
Cylindrical Roller ◽  
Oil Film Pressure

A calculating model for roller-pocket rotation and mechanics analysis is established to investigate the hydrodynamic lubrication between rollers and straight-sided cage pockets in a cylindrical roller bearing. An algorithm for calculating roller-pocket oil film pressure and film thickness is developed. Hydrodynamic lubrication simulation of the roller-pocket clearances is carried out. Effects of inner ring rotation speed, cage angular acceleration, roller profile and cage geometry on roller-pocket oil film performance are numerically studied. Some regular curves and conclusions are obtained and analyzed.

scholarly journals On the Temperature and Lubricant Film Thickness Distribution in EHL Contacts with Arbitrary Entrainment

Lubricants ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 101 ◽  
Author(s):  
Milan Omasta ◽  
Jakub Adam ◽  
Petr Sperka ◽  
Ivan Krupka ◽  
Martin Hartl
Keyword(s):  
Film Thickness ◽  
Thermal Effects ◽  
Film Formation ◽  
Thickness Distribution ◽  
Thickness Measurement ◽  
Lubricant Film ◽  
Operating Conditions ◽  
Lubricant Film Thickness ◽  
Machine Parts ◽  
Film Thickness Measurement

An understanding of mechanisms which are responsible for elastohydrodynamic lubricant film formation under high sliding conditions is necessary to increase durability of machine parts. This work combines thin-film colorimetric interferometry for lubricant film thickness measurement and infrared microscopy for in-depth temperature mapping through the contact. The results describe the effect of operating conditions such as speed, slide-to-roll ratio, ambient temperature, and sliding direction on lubricant film thickness and temperature distribution. Film thickness data shows how much the film shape is sensitive to operating conditions when thermal effects are significant, while the temperature profiles provides an explanation of this behavior.

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